Condenser and method of making same



April 9, 1957 .1. KARMAZIN 2,788,195

CONDENSER AND METHOD OF MAKING SAME Filed Aug. 29, 1952 a? I. J 3)United States Patent This invention relates to a heat exchange unit andthe method of producing the same, although not necessarily so limited.

In the manufacture of heat exchange units, pressed sheet metalhas beenused, wherein the tubes for the heat exchange medium are extruded fromsheet metal, the margins of the sheet metal being'used as fins, asclearly illustrated in the Theodore Karmazin application for UnitedStates Letters Patent Serial No. 229,381, filed June 1, 1951, for HeatExchange Unit and Method of Manufacture, now abandoned.

An object of this invention includes the method of forming a pluralityof rows of tubular projections struck from a strip of sheet metal,stacking or superimposing a plurality of strips of sheet metal havingsuch rows or projections struck therefrom and joining two or more tiersof strips by holding the tiers of strips in spaced and aligned relationby a spacer during the brazing operation.

Another object of this invention is to provide a heat exchange unitutilizing tubular projections struck out from a strip of sheet metal toform passages for the heat exchange medium, banks of such units beingheld in aligned relation and properly spaced by metallic spacer membersmounted between the banks during the fusing operation to hold the banksproperly aligned Without buckling and without being deformed.

Another object of this invention is to produce heat exchange units thatare economically produced, without undue waste of material and at thesame time properly aligned, efiicient and dependable.

Other objects and advantages reside in the construction of parts, thecombination thereof and the mode of operation, as will become moreapparent from the following description.

In the drawings, Figure 1 is a fragmentary, perspective view of aportion of a heat exchange unit.

Figure 2 is an end view of a heat exchange unit that may be made fromtwo 2 cores to make a four row heat exchange unit.

Figure 3 is a fragmentary side elevational view of a portion of a heatexchange unit with parts broken away and shown in section.

Figure 4 is a perspective view of a spacing member.

Figure 5 is a top plan view of a sheet of metal having a tubularprojection struck therefrom.

Figure 6 is a cross sectional view, taken substantially on the line 66of Figure 5.

Referring to the drawings, the reference character 10 indicates sheetsof metal having tubular projections 12 struck outwardly from the metal.In the modification disclosed herein, two rows of tubular projectionshave been provided. In order to provide for the proper flow or movementof metal, slits 14 extend between adjacent pairs of tubular projections.This is to provide sufiicient flow of metal, so that when the tubularprojections 12 are formed, the tubular projections will be uniformthroughoutthe periphery. The shape of the tubular projections, which hasbeen shown as round, and the size, have merely been shown for thepurpose of illustration, in that any suitable shape or size may be used.

The number of sheets 10 having tubular projections 12 struck therefromare stacked with the projections of one strip nested into the cavitiesformed by the projections in an adjacent strip, so as to form a heatexchange unit, such as a condenser. A capping member to for each pair ofadjacent tubular projections may be assembled in association with thesheets. Although two rows of tubular projections have been shown on eachsheet, the number is a matter of choice. For example, there may be one,two or three rows, the number depending upon the size and requirementsof the heat exchange unit and upon the available equipment.

After the strips have been superimposed upon each other and the top andbottom members placed in position, or the end members placed inposition, depending upon the arrangement of the finished assembly, theparts are permanently interconnected by a brazing operation utilizingsuitable brazing metal for welding or fusing the parts together. This isa comparatively simple matter when it is only a few strips and only onetier. In the past, it has been common practice when assembling multipletiers, as disclosed in Figures 1 and 2, to first com plete one unit ortier, then a second unit, or tier, this followed by an operation ofjoining the units or tiers together. By assembling several tiers andbrazing all of the tiers simultaneously, the production would be peditedand the cost reduced. However, in the past this has not been feasible,for the reason that in attempting to assemble a plurality of tiers, thetiers buckle and move out of place. This has been overcome by arranginga spacer member, or several spacer members, located between the severaltiers, so as to hold the tiers aligned during the brazing operation.

in the disclosure a tubular member 20 projects between adjacent tiers.This tubular member may be a sheet metal tubular member having a meltingpoint at least slightly higher than the melting point of the brazingmaterial. Instead of a tubular member, a wire may be used, or a rod, ora strip of metal of any suitable configuration. This tubular or spacermember 20 is preferably mounted in one tier of notches 22 in adjacenttiers of strips of metal, so as to economize on space. The spacer member20 remains as a part of the assembly after the brazing operation iscompleted. The spacer member 20 gives the finished assembly additionalrigidity.

By this arrangement, stacks or tiers of strip material several feet inheight may be assembled and several stacks or tiers fused together, soas to form a condenser or heat exchange unit. All of the connectingmembers 16 and the plates 24, which may be referred to as end plates ortop and bottom plates, are assembled together with the necessaryconduits 2.6 before the fusing operation takes place, so that when theassembly is removed from the brazing furnace, the unit is complete.

No attempt has been made to show how the several tubes or passages areinterconnected, as this is determined by the requirements of thefinished product.

As is well known to those skilled in the art, the brazing operationtakes place in the presence of an inert gas or in the presence of areducing gas, so as to prevent oxidation.

The spacers are of a length approaching the depth of the tiers, so thatthe spacer members extend throughout the depth of the superimposedstrips, or practically throughout the entire depth. For some purposesthe spacer members may be slightly shorter, but not much shorter thanthe depth of the tiers.

Although the preferred embodiment of the device has been described, itwill be understood that within the purview of this invention variouschanges may be made in the form, details, proportion and arrangement ofparts, the combination thereof and mode of operation, which generallystated consist in a device capable of carrying out the objects setforth, as disclosed and defined in the appended claims.

Having thus described my invention, I claim:

1. The method of manufacturing multiple tier heat exchange units whichcomprises the steps of forming a plurality of slots in a plurality ofsubstantially fiat sheets of metal with the slots in each sheet arrangedin a column intermediate the side edges of each sheet, simultaneouslyforming a plurality of tapered, tubular projections on each sheet and aplurality of notches in the side edges of each sheet, the projectionsand the notches being arranged in rows aligned with the slots and theprojections being disposed on opposite sides of the slots, superimposinga plurality of sheets to form a tier with the sheets disposed in spacedsubstantially parallel planes and the projections on the sheetstelescoping together to form elongate tubes, mounting at least two tiersin side by side relationship, positioning a straight tubular member inthe notches between adjacent tiers with the adjacent side edges of eachsheet in each tier frictionally engaging the tubular member so as tohold the sheets of the tiers in aligned relationship, and simultaneouslybrazing the telescoping projections together and the edges of the sheetsto the tubular member to form a unitary structure.

2. A heat exchange unit comprising, in combination, a plurality oftiers, each tier including a plurality of substantially flat sheets eachhaving a plurality of tapered tubular projections integral therewith,said sheets being superimposed with the sheets of each tier disposed inspaced substantially parallel planes and the projections telescopingtogether and forming tubes, the side edges of each of said sheets havingnotches therein aligned with the projections, and a straight tubularmember positioned in the notches between the adjacent tiers with theadjacent side edges of each sheet in each tier engaging the tubularmember, said telescoping projections being brazed together and the edgesof the sheets being brazed to the tubular member to form a unitarystructure.

References Cited in the file of this patent UNITED STATES PATENTS ug- M,

